When one desires to establish a disconnectable digital link between two electronic subunits (such as for example two printed-circuit electronic cards) comprising active components capable of processing high-speed digital information, it is necessary to interpose between these two subunits at least one pair of connectors with male and female pins, respectively. These connectors must be designed so as not to impair the quality of the signals transmitted at high speed. One generally speaks of high-speed digital information when said information is transmitted at a rate of the order of 100 megabits per second or more.
These connectors must be designed so as not to impair the quality of the signals transmitted. An advantageous solution consists in mounting one of the connectors directly on the card. In this case, such a connector must be engineered to ensure good protection in relation to outside electromagnetic disturbances and to modify as little as possible the predetermined constant impedance of the transmission lines generally used at such speeds. It is recalled that the shielded cables used for these high-speed links exhibit a characteristic, constant impedance. The connector must therefore be engineered so that this impedance does not vary significantly at the linkup level. Stated otherwise, the transition between the connector and the printed circuit must be impedance matched.